1. Field of the Invention
The present invention relates in general to the field of information handling system device connections, and more particularly to a system and method for detecting false positive information handling system device connection errors.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems typically incorporate or interface with a variety of storage devices, such as hard disk drives, tape drives, or optical drives. Storage devices are typically built into the chassis of the information handling system so that, like other internal components, the storage devices receive power from the information handling system power subsystem and communicate information over internal buses. Alternatively, storage devices run as external separate systems that connect to the chassis of the information handling systems through physical connection. For example, one or more storage devices are sometimes configured as JBODs or RAID systems that provide enhanced storage for an information handling system server, such as a server configured to support a storage area network (SAN). To simplify the connection of storage devices, industry developed standard communication protocols for storage devices to use. A widely accepted storage device protocol is the SCSI protocol. Recently, in order to improve the speed at which storage devices communicate information, industry has developed a serial link protocol for supporting storage device communication know as the Serial Attached SCSI (SAS) protocol. The SAS protocol provides the more rapid information transfer rates available with a serial link while continuing to use the commands defined by the SCSI protocol. In addition, the SAS protocol supports the hot insertion and removal of a storage device to an information handling system. A wide variety of devices may support the SAS protocol with hot insertion and removal for plug and play communication of information to an information handling system, such as facsimile devices, scanners and copiers.
Typically, information handling systems monitor SAS device connections for errors in the information communicated with SAS devices. For instance, an SAS Phy Error Log Counter tracks errors across an SAS connection as the errors occur to predict a failing device connection. For example, the rate-of-change of the SAS PHY Error Log Counters are monitored in an SAS environment to detect failing connections in the SAS Service Delivery Subsystem, target devices and other components of an SAS solution set. Thus, an increased rate-of-change of detected errors above a predetermined threshold triggers an error warning to the end user or to information technology administrators who are monitoring the equipment. However, hot insertion and removal of target devices in an SAS environment sometimes causes the Phy Error Log Counters to increase dramatically over a short period of time as an active device connects or disconnects with the SAS link. Generally, the normal insertion and removal of an SAS device is not distinguishable from a failed or failing device or connection using existing SAS protocol methods, such as BROADCAST(CHANGE) SAS primitives. Generation of false positive SAS link failure warnings causes end user confusion and unnecessary maintenance, such as end user calls for technical help to the manufacturer of the information handling system or SAS device.